This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -144 |
| 2 | 8208 |
| 3 | -225216 |
| 4 | 2634192 |
| 5 | 1488672 |
| 6 | -209742912 |
| 7 | -503961984 |
| 8 | 8575185744 |
| 9 | 91347182640 |
| 10 | 524570699232 |
| 11 | 2230073940672 |
| 12 | 7794083954880 |
| 13 | 23627036677536 |
| 14 | 64145226215808 |
| 15 | 159373702203264 |
| 16 | 368012313906768 |
| 17 | 798872890993632 |
| 18 | 1644874069475664 |
| 19 | 3234829827767616 |